Category: Arch Linux

more rp3 work

whbeebe
TWM running on Arch Linux ARM and Raspberry Pi 3

I surprised myself by how little time and effort was required to bring TWM and X back up on Arch Linux running on the RP3. This time around I didn’t try to install any other DE, just TWM. I had copies of my earlier TWM setup on my Ubuntu notebook, so I was able to simply mount the boot volume and make copies into the alarm account. I’ve had to make some minor tweaks to .twmrc, specifically disabling AutoRaise on everything. I discovered that automatic raise where the window pops to the top as soon as the mouse passes over it was a real annoyance, not the nice feature I thought it was in earlier incarnations. I also discovered I had to disable it because I couldn’t fully resize the xterm window. Now everything is back to something useful.

Here’s the list of packages I installed:

  • xorg-xinit
  • xorg-twm
  • xterm
  • xorg-server (note: this comes up asking to chose a repositor to load from; take all defaults)
  • xorg-server-utils
  • mesa
  • xf86-video-fbdev
  • xf86-video-vesa (at this point you can bring up twm)
  • xorg-oclock (this may change; need a better desktop clock for the time)
  • xorg-xeyes
  • xorg-xload
  • xv

Support packages I also installed:

  • scrot (for screen shots)
  • vim (a better vi)
  • python3 (the best Python, and it becomes the default in the environment)

To support WiFi, I installed

  • iw
  • wpa_supplicant
  • dialog

After installing for WiFi, I did the following

  • Run wifi-menu to find the local hotspot gateway and enable wifi the first time
  • netctl enable wlan0-[my_gateway_name] to enable WiFi on startup

I need to dig a little deeper into TWM. In particular I want TWM to remember what windows were up and running from prior sessions so that when I start TWM via startx the desktop comes back up the way I want it. I can hard-code some windows and their positions, but I want something more dynamic from session to session. I’ve also NOT installed emacs and medit, as vim is just fine, thank you very much. All I need to install now to get back to where I left off a while back is node.js and its various support packages for GP i/o. Then I need to move on to more than just flashing lights. Something a lot more IoT-ish, something that’s robust against many of the malevolent actors currently out on the Internet (Russia, N. Korea, Iran, NSA, FBI, and GCHQ, just to name a few).

I’m also thinking of creating and supporting a disk image that others can download with all these in place. I tried this once before but gave it up because of the original Arch Linux disk image. But that official disk image is no longer supported. Getting Arch Linux on a Raspberry Pi requires sophisticated Linux skills and experience, way beyond the typical beginner of a Raspberry Pi. This time, unlike the first time, it will be a complete basic install with GP i/o, WiFi, and TWM support installed. I’m also going to support a full 32GB image (compressed via ZIP for easier download).

I’m also going to support the older RP2 while the code still can. Once Arch Linux ARM officially goes 64-bit for RP3, then I’ll probably drop support for RP2.

I’m still playing catchup. Sorry for repeating things here I wrote about over the past few years, but at least it’s been tested with the latest Raspberry Pi 3 board.

raspberry pi 3 – the adventure continues

whbeebe

I spent some time this evening running the Raspberry Pi 3 (referred to as RP3 from here on out) through some paces, starting with bringing up the i2c interface. I’d done this early on with the original Raspberry Pi a little over two years ago using the Arch Linux distribution. I followed those directions but with Raspbian as the target distribution, and I failed to enable the i2c buss.

Rather than spend an inordinate amount of time trying to debug Raspian I grabbed the second of my 32BG Samsung micro SDHC cards and following the directions on the Arch Linux | ARM wiki, I created a bootable Arch Linux card and brought up the RP3 under Arch Linux for ARM. The current page for the RP3 instructions states up front this is the older 32-bit ARM release. Because this is a bare-bones distribution compared to Raspbian, the RP3 needed to be hard wired into my network in order to update the distribution as well as install additional packages, such as support for WiFi. I should note that it was simple to install Arch Linux WiFi support, and when it was installed, it enabled the RP3’s internal WiFi network. Once that was up and running I pulled the network cable and carried on.

I installed the same packages for the RP3 as I did for the original Raspberry Pi, and when I went back to reboot it, I didn’t see the i2c buss. I did a little digging and discovered I had to edit the /boot/config.txt file on the RP3, making the following changes to the file:

  • uncomment device_tree_param=i2c_arm=on
  • uncomment device_tree_param=i2s=on
  • uncomment device_tree_param=spi=on

With those three lines uncommented and with the necessary drivers installed from the earlier packages /dev/i2c-1 was finally enabled.

I should note that the same Arch Linux ARM micro SDHC card boots both the RP2 as well as the RP3.

I should also note that I needed to fix how the Apple aluminum keyboard worked as I documented here.

Because the RP3 requires more power than any other Raspberry Pi to date (5v at 2.5A), I’m using an Apple 12W USB power adapter. I’ve got more than a few around the house these days, and their output is rock solid and clean. So far it runs the bare bones system without anything else attached.

Next steps will be to install X and TWM. Or I just might use the seven virtual keyboards that work now (one of the benefits of a properly configured Apple keyboard).

I’m trying to move as fast as I can to catch back up to where I was back in 2014. I’m working towards an IoT framework around Arch Linux with baked-in encryption. For real this time.

And maybe, just maybe, add a dash of some of the CoreOS features that have caught my fancy. A lot has happened these past two years, and I have a lot of serious catching up to do.